Abstract
Peroxisomal disorders have been associated with malfunction of peroxisomal metabolic pathways, but the pathogenesis of these disorders is largely unknown. X-linked adrenoleukodystrophy (X-ALD) is associated with elevated levels of very-long-chain fatty acids (VLCFA; C>22:0) that have been attributed to reduced peroxisomal VLCFA β-oxidation activity. Previously, our laboratory and others have reported elevated VLCFA levels and reduced peroxisomal VLCFA β-oxidation in human and mouse X-ALD fibroblasts. In this study, we found normal levels of peroxisomal VLCFA β-oxidation in tissues from ALD mice with elevated VLCFA levels. Treatment of ALD mice with pharmacological agents resulted in decreased VLCFA levels without a change in VLCFA β-oxidation activity. These data indicate that ALDP does not determine the rate of VLCFA β-oxidation and that VLCFA levels are not determined by the rate of VLCFA β-oxidation. The rate of peroxisomal VLCFA β-oxidation in human and mouse fibroblasts in vitro is affected by the rate of mitochondrial long-chain fatty acid β-oxidation. We hypothesize that ALDP facilitates the interaction between peroxisomes and mitochondria, resulting, when ALDP is deficient in X-ALD, in increased VLCFA accumulation despite normal peroxisomal VLCFA β-oxidation in ALD mouse tissues. In support of this hypothesis, mitochondrial structural abnormalities were observed in adrenal cortical cells of ALD mice.
Original language | English (US) |
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Pages (from-to) | 744-753 |
Number of pages | 10 |
Journal | Molecular and cellular biology |
Volume | 23 |
Issue number | 2 |
DOIs | |
State | Published - Jan 2003 |
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology